I'm a little confused. As has often been discussed here, it seems that the physiology of light perception is such that the brightness of pulsed light from an LED will usually be perceived as much brighter than would be the case if the same average current were flowing continuously, in some cases maybe to the extent that the perceived brightness approaches the brightness of the individual pulses.
This is what we found in University, we were given an exercise, using a 555 timer we would over drive so net power was same, the LED's seemed brighter, however the lux meter showed no change.
As already mentioned, there are 4 wires (minimum) for PoE - the later standards allow use of all 4 pairs for power (but not in 802.3af and 802.3at currently in use for such things).
Yes, one man's feature is another man's (or woman's) gimmick. Myself and SWMBO tend to have differences of opinion even over simple things like whether to have a dimmer for the main living room lamps
Indeed. Unfortunately the vast majority of people dislike the idea of running cables and insist on the much inferior wireless connections
Mother was looking at a new build, and commenting on the absence of any provision for phone or data I got the reply (from the penny pinching developer who wouldn't even put in ducting for phone lines while it would have been easy to do) that "everything's wireless these days" Sadly yes, a lot of stuff will be wireless with all the problems that brings.
With a quick search, I came across this document that discusses the changes and reasons.
Not sure about being out of scope for DIY - many of them come as "plug together" kits that are easier to wire than using long strips where you have to solder the connections or remember to buy the little connectors.
Well I can assure you that it's the standard method of dimming in most applications - partly for the colour rendering aspects mentioned. It's also a lot easier to do, and more efficient, in terms of electronics - just needing a power switch without need for heavy heatsinking.
True, but the cable between switch and light is also generally only supply power to one light even with 230V and 1mm T+E.EDIT: Not to mention that each device is supplied by it's own cable - so while each cable may be smaller, it's also only supplying one device. A bit like going back to the days of "one fuse, one radial, one socket"
Indeed so, and one has to remember that the majority of technological 'features' which have come to be taken for granted are in no way 'needed' - but that doesn't alter the fact taht some will regard them as 'gimmicks'
Dunno. It has certainly (and with good reason) been the norm for dimming of incandescent lamps - indeed, even standard ubiquitous 'analogue' dimming is really nothing more than a variant of 'PWM'. However, when it comes to LEDs, physiology says that human eyes tend to judge brightness of pulses by their peak intensity, and people like eric who have 'done the experiment' (in a classroom or wherever) seem to have largely confirmed that - which has to make one wonder how good PWM is at achieving human-perceived LED dimming! If/when I have some time, I might try some experiments myself!
It's obviously bound to work to some extent. It just seems to me, on the basis of what I'm being told, that a given change in mark-space ratio is likely to have much less effect of 'perceived dimming' with an LED than with an incandescent lamp. That, in turn, suggests that effective PWM dimming of LEDs might require such low mark-space ratios that flickering could become an issue.
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